Tractor trailer assembly



Jan. 16, 1945u s. B. wlNN TRACTOR TRAILER ASSMBLY Filed Aug. 3, 1942 3 Sheets-Sheet l attorneys jam E6, E945. s. 5. WINN TRAGTOR TRAILER ASSEMBLY 3 Sheets-Sheet 2 Filed Aug. 3, 1942 (Ittornegs Jan. E6, 1945. s. B. wlNN 4 TRACTOR TRAILER ASSEMBLY Filed Aug. 5, 1942 5 Sheets-Sheet 5 ,f .IJH ,1 :irri: EN

Snveutor Cttornegs Patented Jan. 16, 1945 UNITED STATES PATENT OQFlFI CE TRACTOR TRAILER ASSEMBLY Sidney AB. Winn, Lapeer, Mich. Application August 3, 1942, Serial. No. 453,349

(Cl. ZBO-331) v 17 Claims.

The present invention relates to tractortrailer combinations, and more particularly, to a safety fth wheel coupling therefor.

The primary object of the linvention is to'/provide a coupling for articulated vehicles. whereby trolled by the vlowering and elevation of the trailer prop to facilitate the easy coupling and unooupling of the component coupling elements without requiring additional work on the Dart of the operator.

Another object of the invention is to provide a coupling ofthe abovennentioned character in which a locking 'sleeve is movably `mounted on the king pin adapted to vbe projected and retracted to its respective locking and 'unlocking ,positions by operation of the trailer props 'so that the coupling sleeve will be. automatically operated during the coupling an'd unjcoupling 'of the tractor-trailer combination.

Another ob'ect of the invention resides in providinga locking sleeve of the above-mentioned character which will receive m'ost 'o f the stresses and strains on the Ycoupling or fifth wheel connection upon failure of the king pin connection and thereby relieve the king pin of considerable wear resulting from such stressing Vandl 'strain'- ing at the fifth wheel connection.

Another object of the invention is to provide a fifth wheel coupling for tractor trailer assemblies wherein 'it will bel impossibleto separate 'the tractor from the trailer' unless the trailer prop is in its trailer supporting position. Y

Another obieo-t of the invention is to provide a coupling for tractor trailer assemblies in which the king pin will be protected' against shearing, particularly when 'the 'trailer tends "to over-#ride the tractor in case of a head-on collision.

Other objects 'and advantagesof the invention will become apparent during the course or the following description of the accompanying draws-A ings wherein:

v Figure 1 is a toppplan view of a trailer-tractor assembly illustrating one embodiment of the irrvention;

Figure 2 'is a side elevational view partly broken away'further showingy the details of'c'onstruc'tion of the tractor-trailer assembly adja cient the fifth wlfieelV ycoupling thereof;

AFigure 3 is .a vertical cross sectional viewtaken on line 3-3 of .Figure 2 looking in the direction of the arrows showing a 4trailer-prop andfits con-- nectio-ns with :the fifth wheel coupling sleeve.;

figure ,4 is an enlarged fragmentary top elevational View of the fth wheelelemen-ts illus,- trating the manner in' which the 'invention AiS applied thereto; g i l fgure 5 is a vertical cross-sectional view taken on line 5--5 of AFigure2Nlooking in the direction of the arrows, .further illustrating the invention in detail; y K A Figure 6 is avertical longitudinal cross-seotional view taken on line 6,-.-6 of AFigure -1 llookingin the directionlof the arrows illustrating the details of the invention and showing the locking sleeve in operative position;`

Figure 7 is, an enlarged fragmentary topolo-r vational view of the king pin'and locking `sleeve showing the control linkage therefor;

Figure 8 is a similar view showing the linkage removed to more clearly illustrate the structure ofthe casting.;

Figure 9 a perspective view of the locking sleeve. showing 'the general construction andarrangement thereof; n

Figure 1'0 is a vertical, erossfseo'tionai view similar to' Figure 6 illustrating' the locking sleeve in vits kelevated or inoperative position;

Figure 11 is a top plan view of a modified form ofthe invention showing a difleren'tfprop and locking sleeve linkage;

Figure 12 isa side eievauonm view of therfonn of theV invention shown in Figure 1l illustrating portions broken away to more clearly reveal the` details of construction; and

Figure 13 i's a vertical Across-'sectiora'l view taken on une la-ls of Figure 12 looking in the direction of the arrows showing a modified linkage structure between the locking sleeve 'and trailer prop.

General construction and arrangement The invention consists of a'` locking sleeve con'- centrically` arranged 'on A`the pin of' va vtrac tortrailer vcombination fifth "wheel construction and slidable relative thereto tol facilitate the locking of the king pin within the slot vof the nf-th wheel. so thatA the king pin will not be acclidentally displaced resulting in theuncoupling of the articulated assembly and' causing considerable damage and possible loss o'f life. Further;

.' the; invention 'includes' linkage connecting the lowering of the locking sleeve to its operative position. Likewise, when the vehicle is at rest and the prop is lowered incident to the uncoupling of the assembly, the locking sleeve will be moved to its inoperative or elevated position to allow the tractor-trailer assembly to be uncoupled in the usual manner. By reason of the cooperation between the component coupling members, the centering of the locking sleeve is facilitated during the coupling operation of the tractor-trailer assembly. Whereby the lockingA frame generally designated as at I3 and includes l parallel side chassis bars I4 connected throughout their length by transverse channel irons I5, I6, I1, I8 and I9. In the rear portion of the trailer chassis I3 is provided spring suspension means for accommodating the usual rear wheels 2|. The forward portion of the chassis I3 is offset as at 22 to provide a forwardly projecting portion 23 which is adapted to overlie the rear end of the tractor chassis I0.

Suitably trunnioned on the rear portion of the tractor chassis I is a tiltable fth wheel ramp 24 and said ramp is provided with downwardly depending lugs 25 integrally formed at each side thereof providing bearing members. Mounted on each of the chassis frame bars I I) is a plate 26 held in place by U-bolts 21 extending around the chassis frame bars ID so that the free ends may be received in lugs 28 formed on the plate 26 and held in place by nuts or the like threaded on the free ends thereof. The plate 26 is provided along its edges with upstanding flanges 30 between Which is received the depending lugs 25 ofthe fifth wheel ramp 24. Suitable bearing bosses 3| are formed on the side anges 30 and are adapted to receive a pivot pin 32 which extends through an opening in the lugs 25 whereby said platform 24 may rock or tilt rearwardly and forwardly. The tilting fth wheel ramp 24 is provided with rearwardly extending wings 33 having inwardly converging walls 34 terminating in a slot 35. The slot 35 is enlarged as at 36 to provide a circular kingpin opening. Further, the tiltable fth wheel .platform 24 is provided with a marginal depending ange 31 to reinforce and strengthen the tiltable platform. The extreme rear ends of the wings 33 are inclined as at 38 to facilitate the guiding of the trailer chassis I3 into proper position for the coupling'of the component coupling members.

v Depending from 'the under surface of the tiltable fifth wheel platform 24 is a pair of oppositely disposed brackets 39 formed integral with the under surface and said brackets are connected by a bottom wall 49 having a circular recess or cut-away .portion 4I. Likewise formed on the under surface of the tiltable platform 24 is a pair of bearing bosses 42 on opposite sides of the circular king-pin opening 36 and said bearing bosses are adapted to receive boltsor the like as at 43 which extend through Aopenings in the tiltable platform 24 and have their heads received ln countersunk bores 44. The opposite ends of the bolts 43 extend through the connecting wall 40 and are provided with nuts or the like as at 45 threaded on the ends thereof. Pivotally mounted on each of the bolts 43 is a plate-like member 46 having arcuately-curved cutaway portions 41 providing king-pin retention jaws 48. The platelike members 46 are pivoted so that the forward portions 49 may separate a distance sufricient to allow the king-pin to be moved into the slo-t 35 and thereby allow the kingpin to be moved into engagement with the retention jaws whereupon continued movement of the kingpin will' elect the closing of the jaws therearound into the position shown in Fig. 4. Each of the platelike members 46 is provided with a tail-piece 50 cut away as at 52 to provide a complementary notch for receiving a locking bolt 53. The locking bolt 53 is provided with a longitudinal slot 54 slidably received on an integral projection 55 depending from the bottom wall of the tiltable platform 24. A washer 56 isbolted or otherwise fastened in place by means of a screw 51 to facilitate the correct positioning of the locking bolt 53. The opposite end of the locking bolt is provided with an offset portion 51a terminating in a, plunger 58 slidably received in an opening 59 in the marginal flange 31. A coil spring 60 has one end abutting the ange 31 while its opposite end is in abutting relation with the offset portion 51a of the bolt 53 to normally urge the end of the bolt 6I into engagement with the complementary notch 52, thereby holding the king-pin locking jaws 48 in engagement with the king-pin carried by the trailer which will hereinafter be more fully described.

A rock-lever 62 is pivoted to a pivot pin 63 formed integral with the under surface of the tiltable platform and one end of said rock lever is provided with an arm 64 having a slot 65 for receiving a ,pivot pin 66. 'Ihe pivot pin 66 may be held in place by means of a transverse cotter key 61 as is clearly shown in Figure 6. The opposite end of the rock lever 62 is provided with an actuator lever 68 having a bifurcated end 69 for receiving the end of the rock lever 62 and said bifurcated portion 69 is securely fastened to the rock lever by means of a bolt or the like as at 10. The actuator lever 68 is provided with a handle portion 1I which projects through a notch in the marginal flange 31 so that the actuator lever may be accessible from a position on either side of the tractor chassis I0.

The forward portion of the trailer chassis I3 is provided on its under surface with a plate 12 extending between the transverse channel irons I8 and I9 and being preferably welded or otherwise secured thereto. The forward portion of the plate 12 is inclined upwardly as at 13 and is adapted to contactually engage the inclined surface 38 of the tiltable fth wheel platform 24 when the trailer and tractor are being coupled or uncoupled. An opening 14 is centrally formed in the plate 12 and said opening is adapted to receive an annular flange 15 formed on a circular plate 16. The annular flange 15 may be secured within the opening 14 and held there by means of bolts or the like as at 11 extending through the circular plate 16 so that the free ends of the bolt 11 will be threaded in correspondingly threaded openings in the plate 12. Formed integral with the circular plate I6 is an annulus .18 havingA aV cylindrical inner wall surface 1.9 in registry with the circular k-ing pin receiving opening x38 fin the tiltable f-th wheel platform `24. A sking pin supporting `sleeve 80 is mounted within the .annulus 1-8 and :is supported concentrically thereof :by means of integrally formedconnecting wings 18|. The uppermost ends of the king-.pin lsupporting sleeve .is threaded as vat -82 for receiving .the upper threaded end of a king pin 8-3 as at 84. The king pin 83 projects downwardly .and is provided with a head 85 Iadapted to underlie the king pin grip-- ping jaws 48 as is best shown in Fig. 5. It is tobe noted that the king pin 83 extends .a considerable distance below `the undersurface of the .tiltable platform 24 so A.that the free end .thereof will vbe in registry with the separable .king pin engaging jaws 46. Likewise, `the king pin supporting sleeve 80 extends downwardly .a distance slightly greater Vthan the .annular flange 15 and said sleeve 80 is of a diameter slightly less 'than the distance between the walls of the slot 35 to facilitate the entrance of the sleeve 8.0 into the circular opening 36.

Slidably mounted between the annulus 18 vand the king pin supporting sleeve 80 is a locking sleeve '8B and said sleeve `is provided with longitudinal cutaway portions 81 dening diametrically opposed longitudinally extending slots r81. The longitudinal slots 81 are adapted .to receive the diametrically opposed connecting wings 8| to allow the free reciprocable movement of the locking sleeve 88 into and out of the circular opening 36. Diametrically opposed bearing bosses 88 are formed on the locking sleeve 86 adjacent the top edge thereof and pivot pins v89 are fastened in said bosses by means of locking pins or the like as at 90. The circular plate 16 is provided with spaced upstanding ears 9| between which is pivotally supported a control member including a cylindrical portion 92 having formed integral with the, ends thereof lever arms 93. The tubular member/92 is adapted to receive -a supporting shaft 94 the 'free ends Vthereof extending through suitable'openings 95 inthe upstanding ears 9| so that the spaced Aarms 93 will rock in unison. The free ends of the arms 93 are `provided with openings 96 for receiving the vpivot pins '89 land said openings 95 are slotted to allow free play between the pivot Ypin 89 and the slot when the `arms 93 are rocked on their shaft 94. Cotter keys or pins 91 lare provided `lin the ends of the shaft 94 to lsecurely -hold said shaft Vin positionand a set screw 98 is threaded in lthe upper end of ythe king pin supporting lsleeve 80 so that the inner end vof the setscrew will engage lthe threaded portion .84 of the king pin and securely lock the :same in position.

`Formed integral with the tubular member V92 is an upstanding lug 99 adapted .to receive a clevis L which is bolted .in place by means of a .bolt |0I. The clevis |00 ,is provided with a rearwardly extending rod |02 so that the rear end of the 4rod may likewise be provided with a clevis |03 so that the rod maybe coupled toa trip lever |04. Also projecting from the tubular portion 92 is a lug |05 which is engaged by a spring-.Dressed plunger `|06 slidably received in a circular housing |01 formed integral `with extension I 08 on lthe circular plate 16.

The trip lever |04 is .supported by .a bracket |09 having a base portion IIO welded yor other- .wise secured to the transverse channel bar I1 .and Vthe free end of which bracket is provided with spaced bearings .|.I| between .which is rockably mounted a bearing collar ||2 formed' onl the "upper :end of the trip lever |04. The clevis .|03 is "bolted or otherwise secured to the inten.- mediate portion of the etrip rlever .I 04 and a bear.- ing pin .'I I3 -is adapted to pivotally :support vthe trip lever by yextending through 'the spaced .bear-.- ing members `I III and through fthe 'bearing collar I-I2. The lower lend of the trip lever is fprof-` vided Ywith an arcuately curved lcam, face .|44 which -is adapted Yto be Aengaged by an Iactual-,or lever which Vwill ,be `hereinafter more fully .defscribed..

:Depending 4from the vertically :offset portion 22 of each trailer A.chassis frame member I4 `a bracket |I5 secured place 4by v rivets `or `the like and the lower ends of each Abracket :are .pro-

vided with Ybearing .bosses .-|lI6 for :receiving a shaft |I1. Pivotally mounted .on .the -shaft .I,I.1 adjacent veach end thereof is a prop .bar I |9 .one end of which is provided with .a :collar 1I|9 sur.; rounding said shaft |I1- so .that free .swinging movementyof .the prop bar -IfI can be facilitated. Likewise, bearing bosses l| are formed `on the lower end of each prop .bar |I8 for l supporting an .axle If2| .having wheels .|22 rotatably mounted -on the projecting vvends thereof. '.'Ihe lower ends Vof the prop bar I|8 may be connected .by .a tubular connecting bar |23 through which said axle |2I extends as :is clearly .shown `in Fig. 'l .and Fig. 2.

vEach of the prop ,arms |.I.8 is provided ,with a lug for pivotally receiving the lower `en ds .of converging guide ,bars .|28 which `may be integrally connected at their .converging points so that a pivot pin |21 may connect saidfpointjto a sliding guide block |28 connected to a. ,slide rod |29 Vguided yin a conventional prop arm actuator |30 at one end and in a suitable opening in the transverse channelbeam rI5 at the opposite end.

Mounted .intermediate the .ends of the shaft II1 is a .trip lever engaging finger I3I whichjis presented directly .beneath the trip lever |04 so that Ythe free end thereof will engage the arcuately curved surface I|4 ,and thereby rock said trip lever, at the same time causing the movement of the rod -|02 'resulting in 'the elevation of the locking sleeve 86. It is .to .be noted that the collar '|32 of 'the tripfnger I3I is secured tothe rock shaft YI"I1"by"m'eans vof a pin |33 and the bearings ||9 of the prop arms I I8 are similarly connected as Aby means of pins or the like as at L|34 whereupon swinging motion .of the prop arms II8 will effect the rocking motion of `the shaft I1 with the result that 'the tripping nger |3'I will `be`moved into :and out V0f engagement andtripping relation with'the tripping vlever |04.

In operation, the trailer will be assumed to be unconnected from the tractor wherein the trailer will be normally supportedb-y the prop arms II8 to cause the trailer to `assume a horizontal v,position. When lit is desired to couple thetract'or and trailer, the tractor is moved rearwardly softhat the tilting vplatform 24 is moved directly under `the supporting plate 12. As this occurs, the king.- pin 83 enters the vconverging vslot 34 and upon continued rearward movement of the tractor, the king-pin is finally received in the circular opening 36 and is held spaced therefrom by means of the king-pin clamping jaws '46. 'When the actuator |30 is controlled 'to operate the slide rod |29, the props II8 will be moved to their unsupportingposition, 4and during such `movements the tripping finger I3I will move `away from the tripping lever |04 and thereby allow the .Spring pressed plunger |06y to Adraw the Nrod .|02 lin a forward r.direction `and yallow ,the 'loking .Sleeve 8.6

to be moved downwardly so that the extreme lower end thereof will fill the space between the annulus 18 and the king-pin supporting sleeve 80 as is clearly shown in Figs. 4 and 5 so that said sleeve will enter the circular opening 36 in the tiltable platform 24. When uncoupling, it is only necessary to manipulate the actuator |30 to allow the slide rod |29 to move forwardly so that the props |8 will move downwardly until the groundengaging wheels |22 engage the supporting surface and during such movement, the tripping finger |'3| will engage the trip lever |04 and cause the rearward movement of the rod |02 thereby elevating the locking sleeve 86 so that the component coupling elements will then be disvconnected by operating the actuator lever 68 to permit the separation of the king-pin engaging jaws 46 when the tractor is moved forwardly with respect to the trailer.

In the form of the invention shown in Figs. 11, 12 and 13, the trailer frame |3 is substantially identical to the trailer frame shown in Figs. 1 and and includes the same spring suspension for supporting the rear wheel and likewise, includes the chassis frame bars |4 connected by transverse channel bars |5, I6, |1, I8 and |9. The coupling elements are likewise the same' and the difference of construction resides in a modified locking sleeve elevating member generally designated |32 supported by the upstanding ears 9| on the circular plate 16. The slotted arms |33 of the modified construction |32 are formed as individual members, said slotted arms are adapted to engage the diametrically opposed pins 89 on the locking sleeve 86 which is also identical to the form of the sleeve shown in Figs. 1 to 10 inclus1ve.

The modied construction |32 includes individual downwardly depending levers |34 to which is pivotally connected a clevis |35 as at |36. reciprocating rod |31 is attached to the clevis as at |38. It is to be noted that the clevis |35 connects the free ends `of the individual arms |34 so that movement of the clevis will effect the operation of the individual arms |33.

ment |38 of the clevis as is clearly shown in Fig. 11.

The modication likewise includes a rock shaft |'l mounted in the same manner as the rock shaft shown in Figs. 1 to'lO inclusive and is supported in the same manner. A lever supporting bracket |09 is likewise fastened as by welding to the channel bar |1 for supporting a modied trip lever |39 to which one end of the rod |31 is connected by means of a suitable clevis |40 pivoted thereto as at |42. The lower end of the modied trip lever |39 is provided with a pair of oppositely eX- tending jaws |43 and |44 for receiving the pin |45 of a modified trip finger |46. The trip finger |46 is secured to the rook shaft ||1 which is identical to the shaft shown in Figs. 1 and 2 and is likewise intended to support the prop lever |8 and the ground engaging wheels |22. The slidable actuator |26 is connected to a clamp |28 fastened to the rod |29 which forms one end'of a plunger operably mounted in the actuator |30 and the props I8 are likewise operative to their extreme positions in the same manner as shown in the form of the invention in Figs. 1 to 10 inclusive. 'I'he modied trip finger |46 has its hub |41 securely fastened to the shaft I|1 by means of a pin |48 and it is to be noted that by reason tof the curved surface |49 between the opposed jaws |43 and |44 that rocking movement of the The rod 'is threaded or otherwise secured in the enlargeprop arms |8 will positively operate the reciprocating rod |31 thereby causing a. locking sleeve 86 to likewise be positively operative between its extreme positions. Further, it is to be noted that the modiiied form of the invention shown in Figs. 11 to 13 inclusive does not rely upon the use of coil springs or a spring pressed lever Drojection |05 as is shown in the form of the invention illustrated in Figs. 1 to 10 inclusive.

Whenthe prop levers ||8 are lowered in the modified form of the invention, the pin |45 operlates between the opposed jaws |43 and |44 to cause the trip lever |39 to rock or swing on its pivot pin carried by the bracket |09. By reason of the fact that the pin |45 more or less follows the curvature |49 of the trip lever, the raising or lowering of the prop levers ||8 will operate the trip lever and the reciprocating rod |31 to effect the positive lifting .or lowering of the locking sleeve 86.

It is to be understood that the form of the invention herewith shown and described are to be taken as preferred embodiments hereof and that various changes in the shape, size and arrangement of parts may be resorted to Without departing from the spirit of the invention or the scope of the subjoined claims.

What I claim is:

1. A tractor trailer assembly having component coupling elements including a king pin for being received in a key hole slot in a fth wheel member, a locking member carried by and concentric with one of said elements to engage the other of said coupling elements and lock the tractor trailer in :coupled relation said locking member being adapted to close said key hole slot against the removal of the king pin and mechanism carried by and operable from the trailer for moving the locking member to its operative and inoperative positions.

2. A tractor trailer assembly having component Coupling elements including a king pin and a slotted fifth wheel member, a slidable cylindrical locking member associated with one of the component coupling elements for reception in said slot in the other element to retain the assembly in coupled relation and trailer supporting mechanism on the trailer operably connected to said locking member for sliding the locking member to an inopertive position upon movement of said supporting mechanism to an operative position.

3. A tractor trailer assembly having component coupling elements including a king pin and a keyhole slotted fifth wheel member adapted to be separably connected, a locking member slidably carried by and concentric with one of the elements for reception in said slot in the other element to maintain the component coupling elements in a locked position, and mechanism operable preparatory to the uncoupling of said tractor-trailer assembly connected to said locking member for moving the locking member to an unlocked position.

4. A tractor trailer assembly having component coupling elements including a king pin and a keyhole slotted fth wheel member for separably connecting said assembly, an auxiliary locking sleeve slidably carried by and concentric with one of said component coupling elements adapted to engage within the key hole slot in the other component element and mechanism operably connecting said locking member carried by the trailer for moving the locking sleeve into and out of engagement with said coupling element.

5. A tractor trailer assembly having component coupling elements for retaining the assembly separably connected, a slidable concentric sleeve carried by one of said component elements, and means on the trailer for moving said sleeve into and out of engagement with the other coupling element whereby the load of the component coupling elements will be transmitted to the concentric sleeve.

6. A tractor trailer assembly having component coupling elements. for separably connecting the assembly, a concentric locking sleeve slidably mounted on one of said coupling elements for being moved into the path of the other coupling element and means located on the trailer for moving the locking sleeve to and from its locking position.

7. A tractor trailer assembly having component coupling elements including a king pin and a slotted fth wheel member for separably connecting the assembly, a locking sleeve carried by one of said coupling elements movable into and out of engagement with the key hole slot in the other coupling element and an actuator adjacent the coupling elements for moving the sleeve to its operative and inoperative positions.

8. A tractor trailer assembly having component coupling elements providing a separable fth wheel construction, a locking sleeve adapted to be carried by one of the elements whereby stresses and strains will be transmitted to the locking sleeve and an actuator adjacent said sleeve to cause the sleeve to be moved into and out of registry between said component coupling elements.

9. A tractor trailer combination having separably connected component coupling elements, a locking sleeve slidably carried by one of said component coupling elements adapted to be moved into and out of an opening in the other element and an actuator vadjacent the coupling elements for operating the locking sleeve.

10. A tractor trailer combination having separably connected component coupling elements, one of said elements comprising a king pin, a locking sleeve slidably mounted on the king pin for movement into and out of an opening in the other component coupling element and an actuator for moving the locking sleeve to its operative position from its inoperative position.

11. In combination with a tractor trailer vehicle having a fth wheel assembly including component pin and slot coupling elements and a prop for the tractor, a locking sleeve slidably carried by one of the coupling elements adapted to be received in the slot in the other coupling element and an actuator controlled by the trailer prop for moving the locking sleeve to its operative and inoperative positions.

12. In combination with a tractor trailer vehicle having a fth wheel assembly and a prop for supporting the trailer in a horizontal position, a locking member carried by the fth wheel to lock the assembly in coupled relation and means operable by the movement of the prop for controlling the locking member.

13. In combination with a tractor trailer vehicle having component king pin. and slot coupling elements separably connected and a prop for holding the trailer in a. horizontal position when disconnected from the tractor, a locking l5 move the locking member to an unlocking position.

lll. In combination with a tractor trailer vehicle having a pin and slot fifth wheel coupling and a ground engaging prop for maintaining the trailer in a horizontal position when uncoupled from the tractor, a locking member associated with the fth wheel coupling adapted to be moved from a locked position between said pin and slot to an unlocked position free of said pin and slot and linkage connecting the ground engaging prop With the locking member whereby movement of the prop will eiect movement of the locking member.

15. In combination with a tractor trailer vehicle having a fifth wheel construction including separably connected component coupling elements and a ground engaging prop for maintaining the trailer in a horizontal position when uncoupled from the tractor, a. locking sleeve inter.-

5 posed between the component coupling elements for slidable movement relative thereto, and linkage connecting the ground engaging prop with the locking sleeve to cause said sleeve to be moved into and out of its operative position upon the 0 raising and lowering of the ground engaging DI'OD.

16. In combination with a tractor trailer vehicle having a fth Wheel construction including r separably connected component coupling elements, a locking member associated with one ol the coupling elements movable toward and away from the other coupling element and adapted to be interposed between said component coupling element and an actuator for said locking member.

17. In combination with a tractor trailer vehicle having component coupling elements wherein one of said elements constitutes a king pin, a locking sleeve reciprocably mounted on said king pin adapted to be moved to -a position between the king pin and the other component coupling element and an actuator for said locking sleeve carried by the trailer. 

